This application claims priority from U.S. provisional application Ser. No. 60/484,740, filed 3 Jul. 2003, the details of which are incorporated herein by reference.
This invention relates to a vibration isolator or resilient mounting, and more particularly to a center bearing isolator mount assembly for damping vibrations, for example, in a motor vehicle, as well as a method of manufacturing and assembling same.
Resilient mountings or bushings generally include an outer rigid member or outer bracket formed with an aperture that receives an inner sleeve or rigid member, and a resilient, vibration damping material such as an elastomer or rubber between the outer bracket and inner sleeve. For example, it is common in the industry to form a resilient mounting of this type, often referred to as a center bearing isolator mount, by stamping an outer metal (steel) bracket in two or more separate metal stamping operations. Outer bracket components or support flanges are then welded to the bracket. An inner metal sleeve or ring is usually formed in a stamping operation. The isolator, i.e., rubber/elastomer, is mold bonded to the outer bracket and inner sleeve. Alternatively, the isolator is mold bonded to the inner sleeve and press fit into the outer bracket.
One drawback associated with the current industry standard is that a large force is required to press fit the inner sleeve with the mold bonded isolator into the outer bracket. There is also a concern with the potential that the mold bonded isolator/inner sleeve may separate or axially move relative to the outer bracket. Moreover, known isolator mount assemblies have significant weight, and a need also exists to improve the overall cost to manufacture and assemble.
Representative patents generally directed to resilient support or shaft bearings, which include vibration isolators, resilient mounts, and center bearing supports are U.S. Pat. No. 2,939,748-Leach; U.S. Pat. No. 3,639,015-Maas; U.S. Pat. No. 3,743,059-Morse, et al.; U.S. Pat. No. 3,961,829-Bowen, et al.; U.S. Pat. No. 4,083,580-Shaner; U.S. Pat. No. 4,722,618-Matsumoto, et al.; U.S. Pat. No. 5,033,875-Moulinet; and U.S. Pat. No. 5,501,531-Hamaekers.
Accordingly, a need exists for an improved vibration isolator and method of manufacture/assembly that meets or exceeds the performance characteristics of known arrangements, and overcomes various problems of the prior art and methods of manufacture/assembly in a simple, economical way, and in a manner that is easy to manufacture.